The overall objective will be to investigate hepatic zinc metabolism using isolated liver parenchymal cells in primary culture. Zinc metabolism will be integrated with the hepatic metabolism of copper and iron as well as with other metabolic events in liver cells. The cells will be isolated by the collagenase perfusion technique from livers of rats of varying dietary status. The biosynthesis of metallothionein will be measured, via metallothionein antibody, as a function of time after glucocorticoid treatment of the cells. The polysomal poly (A+) metallothionein mRNA from batch cultures will be translated in a heterologous system to quantitate changes in synthesis. The kinetics of copper uptake by and efflux from hepatocytes will be measured. The intracellular binding of copper to metallothionein and perhaps other proteins will be investigated as will the relationships of cellular zinc status to these phenomena. The role of specific serum constituents as donors and acceptors of copper, e.g. amino acids, albumin and ceruloplasmin on copper accumulation and efflux will be examined as a function of time. The influence of specific hormones and inhibitors and the competitive influence of zinc and other cations on copper uptake will be examined. The relationship of hepatic iron metabolism and ferritin biosynthesis to zinc accumulation will be investigated, particularly as related to glucocorticoid-stimulated events.